The University of Chicago will no longer require ACT or SAT scores from U.S. students, sending a jolt through elite institutions of higher education as it becomes the first top-10 research university to join the test-optional movement.

Numerous schools, including well-known liberal arts colleges, have dropped or pared back testing mandates in recent years to bolster recruiting in a crowded market. But the announcement Thursday by the university was a watershed, cracking what had been a solid and enduring wall of support for the primary admission tests among the two dozen most prestigious research universities.

The private university in Chicago's Hyde Park neighborhood admits fewer than 10 percent of applicants and ranks third on the U.S. News & World Report list of top national universities, after Princeton and Harvard and tied with Yale. It has required prospective freshmen to take a national admission test since 1957. Before that, it screened applicants with its own tests.

U-Chicago is also expanding financial aid and scrapping in-person admission interviews, which had been optional. Instead, it will allow applicants to send in two-minute video pitches, in an effort to connect with a generation skilled at communicating via cellphone clips.

"Testing is not the be-all and the end-all," said James G. Nondorf, U-Chicago's dean of admissions and financial aid. He said he didn't want "one little test score" to end up "scaring students off" who are otherwise qualified.

The SAT, overseen by the College Board, and the ACT are fixtures in college admissions. Most highly selective colleges and universities require students to take one of them. With some exceptions, the tests remain essential for the vast majority of students who want to attend major public universities. Even schools that go test-optional often find that a majority of applicants submit scores.

In the high school Class of 2017, more than 1.8 million students took the SAT, a three-hour test of math, reading and writing. About 2 million took the ACT, which covers math, reading, English and science in nearly three hours. Both tests have optional essay sections.

Students eager to maximize their college chances often take both exams. But a growing number say having a choice - to submit or not - is empowering.

Yasameen Etami, 18, of Edmond, Oklahoma, is heading to George Washington University in the fall to study public health. Valedictorian of her high school class and daughter of Iranian immigrants, Etami took several Advanced Placement classes and compiled a sterling grade-point average. But she chose not to send GWU her ACT scores - an option for her after the university dropped its testing requirement in 2015.

"They are displaying that students are so much more than just numbers, or simply a three-hour exam that was taken on a Saturday morning," Etami said. She said she took the ACT three times - common these days among college-bound students - and ended up with a satisfactory score. Along the way, she grew skeptical of the entire exercise.

"I often even asked myself who I was doing it for: the universities or to prove to myself that I am capable of succeeding on the exam?" Etami said. "That feeling is one that these test-optional institutions are wiping away."

Debate over admission testing has intensified in recent years. The SAT and ACT were launched in the 20th century with the idealistic goals of rewarding academic merit, breaking social class barriers and giving all students a chance to prove they belong in college. But studies have found a strong link between scores and economic background. Privileged students, with wider access to books, museums, tutors and other forms of cultural or academic enrichment, tend to get higher marks.

Schools that drop testing requirements often say they are doing so in the name of wider access - an assertion that skeptics question. Bowdoin College, a pioneer, went test-optional in 1969, followed by Wake Forest University in 2008, Wesleyan University in 2014 and others. The National Center for Fair and Open Testing lists more than 175 colleges that have become test-optional since 2005.

Still, the College Board, ACT and many admission deans say multiple-choice tests provide useful data in combination with grade-point averages, course transcripts, application essays and other elements of applications. The SAT and ACT scales are broadly known gauges that many admissions professionals find helpful when they sift through thousands of applications and worry whether certain high schools are inflating grades. Few academic credentials grab attention like a maximum score of 36 on the ACT or 1600 on the SAT.

"ACT scores provide a common, standardized metric that allows colleges to evaluate students who attend different high schools, live in different states, complete different courses with different teachers and receive different grades on a level playing field," ACT officials said in a statement.

Recent research suggests that test-optional policies are helping colleges lure more disadvantaged students to apply, although financial aid and other factors play a major role in recruiting.

Skeptics say colleges could have an ulterior motive for dropping test requirements: to raise or solidify their place in national rankings. When testing is optional, average test scores for a school often rise, presumably because fewer low scores are submitted. In addition, applications can rise, which lowers admission rates and makes schools look more selective.

U-Chicago has an ultralow admission rate (7 percent) and high test scores (three-quarters of last year's freshmen who took the SAT scored at least 1480). Officials say their policy shift has nothing to do with rankings.

"It is about doing the RIGHT thing," Nondorf wrote in an email. "Which is helping students and families of all backgrounds better understand and navigate this process and about bringing students with intellectual promise (no matter their background) to UChicago (and making sure they succeed here too!)."

The test-optional policy will apply only to U.S. applicants. Those from overseas - about 16 percent of the applicant pool - still must submit scores. Colleges often rely on testing to help them navigate less-familiar territory in the international market.

Nondorf said the university aims to recruit more students from lower- and middle-income families. Of its 6,000 undergraduates, about 10 percent had enough financial need in 2016-2017 to qualify for federal Pell Grants. That is a lower share than many of U-Chicago's peers.

With the change in admissions policy will come a significant boost in financial aid. The university is announcing a guarantee of free tuition for students from families with income under $125,000 a year. For most students with annual family income below $60,000, financial aid will cover tuition, fees, room and board. U-Chicago's full price for students without aid is more than $70,000 in the coming school year.

The university also announced more scholarships targeting first-generation college students and children of police officers and firefighters.

John Boyer, dean of the undergraduate college, said the university's goal is to provide equal access to elite education - for "all citizens, not just those born in certain Zip codes."